Forms of dementia

The different forms of dementia can be distinguished from one another in different ways or divided into groups. Reference can be made to the localisation of the changes in the brain, to the cause of their development and to the underlying disease. If the degenerative processes occur at certain locations in the brain, they are often followed by typical symptoms which, if localised differently, may not occur until later.

However, the supposedly specific symptoms should not be regarded as evidence of the respective form of dementia. If there is any suspicion, further diagnostic tests must always be carried out in order to gain clarity about the clinical picture. The distinction between primary and secondary dementia is made at the level of the cause of the disease.

If there is primary dementia, the reason for this lies in direct changes in the brain. These can be degenerative (Alzheimer’s disease) or vascular, i.e. vascular. Secondary dementia, on the other hand, is caused by another underlying disease that has nothing to do with the brain.

Diseases of the cardiovascular system, poisoning, metabolic diseases and diseases of infectious, inflammatory or endocrine origin play a role. – Cortical dementia: In cortical dementia (cortex = cortex) the cerebral cortex is affected by the pathological changes. The cerebral cortex, which is located on the outside of the brain, is responsible for many functions.

For example, memory, motor skills, sensitivity and speech are controlled by it. Accordingly, damage to the cerebral cortex results in impaired memory function, limited thinking and speech abilities and motor deficits. The personality, which is particularly controlled via the frontal lobe, is initially less affected.

Frontal dementia: Frontal dementia concentrates on the frontal lobe, which is located at the front of the brain. It is responsible for the formation of the personality and for the planning of actions as well as their consideration. Deficiencies in the frontal lobe lead to strong changes in the patient’s character and often to a negative change in social behaviour.

Planning or organizing thought processes can only take place slowly or not at all. The patient acts in an uncontrolled manner, whereby his intelligence is usually not restricted. The memory is also comparatively well preserved, as is the ability to orientate oneself in space and time.

Subcortical dementia: Subcortical dementia (sub = below, cortex = cortex) exists, as the name suggests, below the cerebral cortex, in the area of the basal ganglia. The basal ganglia are nerve nuclei which serve to process a wide variety of information. Due to the slower processing that occurs in subcortical dementia, the patient’s mental pace is reduced.

He acts and thinks more slowly, can concentrate poorly or react to changing circumstances. Affective disorders complete the clinical picture, through increased irritation, but also a lack of participation and listlessness. Among laypersons, Alzheimer’s disease is often used as a synonym for dementia or vice versa.

This assumption is wrong. Dementia is not a disease in itself, but represents a combination of different symptoms – a syndrome. This syndrome is part of many brain diseases, which are then considered dementia, i.e. they trigger dementia.

Alzheimer’s is the most common of these dementia diseases and is probably why it is so closely associated with the word “dementia”. Approximately 60 percent of all dementia patients suffer from Alzheimer’s disease, but other diseases may also be underlying. Alzheimer’s disease is a neurodegenerative disease (deterioration of the nervous system) that worsens as it progresses. So-called plaques (proteins) accumulate in the brain tissue, which cause the symptoms, sometimes also dementia.